/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.operators;

import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.typeutils.runtime.RuntimePairComparatorFactory;
import org.apache.flink.runtime.operators.testutils.DelayingIterator;
import org.apache.flink.runtime.operators.testutils.DiscardingOutputCollector;
import org.apache.flink.runtime.operators.testutils.ExpectedTestException;
import org.apache.flink.runtime.operators.testutils.InfiniteIntTupleIterator;
import org.apache.flink.runtime.operators.testutils.UniformIntTupleGenerator;

import org.junit.jupiter.api.TestTemplate;

import java.util.concurrent.atomic.AtomicReference;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

class LeftOuterJoinTaskTest extends AbstractOuterJoinTaskTest {

    private static final long HASH_MEM = 6 * 1024 * 1024;

    private final double hash_frac;

    LeftOuterJoinTaskTest(ExecutionConfig config) {
        super(config);
        hash_frac = (double) HASH_MEM / this.getMemoryManager().getMemorySize();
    }

    @Override
    protected int calculateExpectedCount(int keyCnt1, int valCnt1, int keyCnt2, int valCnt2) {
        return valCnt1 * valCnt2 * Math.min(keyCnt1, keyCnt2)
                + (keyCnt1 > keyCnt2 ? (keyCnt1 - keyCnt2) * valCnt1 : 0);
    }

    @Override
    protected DriverStrategy getSortDriverStrategy() {
        return DriverStrategy.LEFT_OUTER_MERGE;
    }

    @Override
    protected AbstractOuterJoinDriver<
                    Tuple2<Integer, Integer>, Tuple2<Integer, Integer>, Tuple2<Integer, Integer>>
            getOuterJoinDriver() {
        return new LeftOuterJoinDriver<>();
    }

    @TestTemplate
    void testHash1LeftOuterJoinTask() throws Exception {
        final int keyCnt1 = 20;
        final int valCnt1 = 1;

        final int keyCnt2 = 10;
        final int valCnt2 = 2;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    @TestTemplate
    void testHash2LeftOuterJoinTask() throws Exception {
        final int keyCnt1 = 20;
        final int valCnt1 = 1;

        final int keyCnt2 = 20;
        final int valCnt2 = 1;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    @TestTemplate
    void testHash3LeftOuterJoinTask() throws Exception {
        int keyCnt1 = 20;
        int valCnt1 = 1;

        int keyCnt2 = 20;
        int valCnt2 = 20;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    @TestTemplate
    void testHash4LeftOuterJoinTask() throws Exception {
        int keyCnt1 = 20;
        int valCnt1 = 20;

        int keyCnt2 = 20;
        int valCnt2 = 1;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    @TestTemplate
    void testHash5LeftOuterJoinTask() throws Exception {
        int keyCnt1 = 20;
        int valCnt1 = 20;

        int keyCnt2 = 20;
        int valCnt2 = 20;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    @TestTemplate
    void testHash6LeftOuterJoinTask() throws Exception {
        int keyCnt1 = 10;
        int valCnt1 = 1;

        int keyCnt2 = 20;
        int valCnt2 = 2;

        testHashLeftOuterJoinTask(keyCnt1, valCnt1, keyCnt2, valCnt2);
    }

    private void testHashLeftOuterJoinTask(int keyCnt1, int valCnt1, int keyCnt2, int valCnt2)
            throws Exception {

        setOutput(this.outList, this.serializer);
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(new RuntimePairComparatorFactory());
        getTaskConfig().setDriverStrategy(DriverStrategy.LEFT_HYBRIDHASH_BUILD_SECOND);
        getTaskConfig().setRelativeMemoryDriver(hash_frac);

        final AbstractOuterJoinDriver<
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>>
                testTask = getOuterJoinDriver();

        addInput(new UniformIntTupleGenerator(keyCnt1, valCnt1, false), this.serializer);
        addInput(new UniformIntTupleGenerator(keyCnt2, valCnt2, false), this.serializer);
        testDriver(testTask, MockJoinStub.class);

        final int expCnt = calculateExpectedCount(keyCnt1, valCnt1, keyCnt2, valCnt2);

        assertThat(this.outList)
                .withFailMessage("Result set size was %d. Expected was %d", outList.size(), expCnt)
                .hasSize(expCnt);

        this.outList.clear();
    }

    @TestTemplate
    void testFailingHashLeftOuterJoinTask() throws Exception {
        int keyCnt1 = 20;
        int valCnt1 = 20;

        int keyCnt2 = 20;
        int valCnt2 = 20;

        setOutput(new DiscardingOutputCollector<Tuple2<Integer, Integer>>());
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(new RuntimePairComparatorFactory());
        getTaskConfig().setDriverStrategy(DriverStrategy.LEFT_HYBRIDHASH_BUILD_SECOND);
        getTaskConfig().setRelativeMemoryDriver(this.hash_frac);

        final AbstractOuterJoinDriver<
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>>
                testTask = getOuterJoinDriver();

        addInput(new UniformIntTupleGenerator(keyCnt1, valCnt1, true), this.serializer);
        addInput(new UniformIntTupleGenerator(keyCnt2, valCnt2, true), this.serializer);

        assertThatThrownBy(() -> testDriver(testTask, MockFailingJoinStub.class))
                .isInstanceOf(ExpectedTestException.class);
    }

    @TestTemplate
    void testCancelLeftOuterJoinTaskWhileBuilding() throws Exception {
        setOutput(new DiscardingOutputCollector<Tuple2<Integer, Integer>>());
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(new RuntimePairComparatorFactory());
        getTaskConfig().setDriverStrategy(DriverStrategy.LEFT_HYBRIDHASH_BUILD_SECOND);
        getTaskConfig().setRelativeMemoryDriver(this.hash_frac);

        final AbstractOuterJoinDriver<
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>>
                testTask = getOuterJoinDriver();

        addInput(new UniformIntTupleGenerator(100, 100, true), this.serializer);
        addInput(new DelayingIterator<>(new InfiniteIntTupleIterator(), 100), this.serializer);

        final AtomicReference<Throwable> error = new AtomicReference<>();

        final Thread taskRunner =
                new Thread("Task runner for testCancelOuterJoinTaskWhileSort1()") {
                    @Override
                    public void run() {
                        try {
                            testDriver(testTask, MockJoinStub.class);
                        } catch (Throwable t) {
                            error.set(t);
                        }
                    }
                };
        taskRunner.start();

        Thread.sleep(1000);

        cancel();
        taskRunner.join(60000);

        assertThat(taskRunner.isAlive())
                .withFailMessage("Task thread did not finish within 60 seconds")
                .isFalse();

        assertThat(error.get()).isNull();
    }

    @TestTemplate
    void testCancelLeftOuterJoinTaskWhileProbing() throws Exception {
        setOutput(new DiscardingOutputCollector<Tuple2<Integer, Integer>>());
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(new RuntimePairComparatorFactory());
        getTaskConfig().setDriverStrategy(DriverStrategy.LEFT_HYBRIDHASH_BUILD_SECOND);
        getTaskConfig().setRelativeMemoryDriver(this.hash_frac);

        final AbstractOuterJoinDriver<
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>,
                        Tuple2<Integer, Integer>>
                testTask = getOuterJoinDriver();

        addInput(new DelayingIterator<>(new InfiniteIntTupleIterator(), 100), this.serializer);
        addInput(new UniformIntTupleGenerator(1, 1, true), this.serializer);

        final AtomicReference<Throwable> error = new AtomicReference<>();

        final Thread taskRunner =
                new Thread("Task runner for testCancelOuterJoinTaskWhileSort1()") {
                    @Override
                    public void run() {
                        try {
                            testDriver(testTask, MockJoinStub.class);
                        } catch (Throwable t) {
                            error.set(t);
                        }
                    }
                };
        taskRunner.start();

        Thread.sleep(1000);

        cancel();
        taskRunner.join(60000);

        assertThat(taskRunner.isAlive())
                .withFailMessage("Task thread did not finish within 60 seconds")
                .isFalse();

        assertThat(error.get()).isNull();
    }
}
